Site description The Sango Bay area, north of the Uganda–Tanzania border, adjoins the Lake Nabugabo area (IBA UG016) to the north. The main road between Masaka and Mutukula at the Tanzanian border marks its western limit; its eastern limit is the Lake Victoria shoreline. There are wetlands, grasslands and forests.In total, the forests within this site cover c.15,000 ha. There are five Forest Reserves: Kaiso, Tero East and West, Namalala and Malabigambo. All are of a rather homogeneous nature, broadly classified as swamp-forest, formerly important for its Podocarpus timber species, most of which have been logged out over the past 100 years. The canopy is generally lower than that of medium-altitude mixed evergreen forest, although many of the component species are the same. The area is considered of biogeographic interest because it lies in the transition between the East and West African vegetation zones. There is evidence that the area was a Pleistocene refugium.The Malabigambo Forest is contiguous with Minziro Forest of neighbouring Tanzania (IBA TZ055). The site also contains a mosaic of wetland types, including permanent and seasonal swamp-forests, papyrus Cyperus papyrus swamps, herbaceous swamps interspersed with palms, and seasonally flooded grasslands. The Sango Bay wetlands are extensive, stretching along the shores of Lake Victoria from Kyabasimba in the south to Malembo in the north. In areas such as Kyabasimba, the shoreline is varied, with sandy shores, rocky shores, forested shores and a fishing village. The shoreline of the bay itself is fringed by papyrus, merging into the extensive flood-plains of the Bukora river delta. The bay is relatively unsheltered and experiences serious wave action. As a result, there is little fringing water-hyacinth Eichhornia, unlike bays in the Entebbe area. At Sango Bay itself, there is a small fish-landing site and an old disused pier, whose structures are important roosts for birds.At the mouth of the River Kagera, the shore is relatively exposed, with mainly sandy shores merging into papyrus swamp. The deposition of silt carried by the Kagera has led to the creation of a wide shallow belt with a sandbar at the river mouth.

Key Biodiversity See Box and Table 3 for key species. About 300,000 Chlidonias leucopterus were reported by the Wetlands Inventory Team in 1994, but this has not been confirmed by later counts. Large numbers of Ardeola ralloides occur in the area. Pelecanus onocrotalus roost at the mouth of the River Kagera in several hundreds and small numbers of Pelecanus rufescens occur. A count of 82 Hirundo atrocaerulea was made in May 2001.

Non-bird biodiversity: Plants of conservation interest include Pseudagrostistachys ugandensis, a grass not known elsewhere in Uganda, and Podocarpus usambaransis vardawei, an endemic variety. Loxodonta africana (EN) is the only globally threatened mammal species found in the area, but near-endemic mammals include Colobus guereza adolfi-friederici, which is restricted to Sango Bay in the Ugandan part of its range, and Cercopithecus mitis doggetti, which occurs at Sango Bay as part of a limited range in south-western Uganda.